Companies that print and/or receive bar code labels often require apparatus for indicating whether the label will be accurately read by a large proportion of bar code scanners. A major factor determining whether the bar code label will be accurately read, is whether there is a sufficient difference in reflectance between the dark bars (usually created by applying ink to a light-colored surface) and the light bars (usually the portion of the original light-colored surface lying between the dark bars). Although a visual inspection of the label is useful, it is also useful to determine how well a bar code scanner or bar code label verifier can read the label. A bar code scanner often produces a display indicating the number read, while a verifier may indicate the number of times the same bar code number was detected, the amount of light detected at each of numerous points along the bar code label, etc. Applicant finds that the relative reflectance of the dark and light bars depends to a large extent upon the precise angle of the scanner or verifier with respect to the plane of the sheet on which the bar code has been printed. A change of angle of only a few degrees can result in a great difference in sensed reflectance. A device which could be used with a hand-held scanner (or verifier which can be considered to act as a scanner herein) would facilitate accurate measurement or determination of the reflectance characteristics of a printed bar code label.